VulnerabilityPublished 28 Sep 2026

CVE-2026-101912: beaugunderson ip-address · Incorrect Comparison

Affects beaugunderson ip-addressSource CVE Database V5

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 10.7.1 when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 4.0 base score

6.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.7.1

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade beaugunderson ip-address to 10.7.1.

Affected software

Product	Affected	Fixed in
beaugundersonip-address	Affected <10.7.1	Fixed in 10.7.1
npmip-address`pkg:npm/ip-address`Other threats	Affected <10.7.1	Fixed in 10.7.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade the ip-address library to version 10.7.1 or later, where the issue is fixed. This update ensures that subnet containment checks validate that both IP addresses belong to the same IP family before comparison, preventing cross-family misclassification.

Description

The ip-address JavaScript library versions prior to 10.7.1 contain a vulnerability in the isInSubnet and isHostInSubnet methods. These methods perform subnet containment checks by comparing masked binary strings without verifying that both addresses belong to the same IP family (IPv4 vs IPv6). This flaw can cause cross-family containment checks to incorrectly classify an IP address as within a subnet when it is not, potentially leading to incorrect allowlist or denylist decisions. The issue is fixed in version 10.7.1.

Impact

The vulnerability can cause allowlist or denylist decisions to misclassify IP addresses outside the intended subnet as contained within it. This may lead to unauthorized access or denial of legitimate access depending on the use of these methods in security logic. There are no known exploits in the wild at this time. The CVSS 4.0 base score is 6.3, indicating a medium severity impact with network attack vector, low attack complexity, and partial impact on integrity.

Summary

CVE-2026-101912 describes a vulnerability in the ip-address library for JavaScript, specifically in versions before 10.7.1. The isInSubnet and isHostInSubnet methods compare masked binary strings to determine subnet containment but fail to validate that both operands are from the same IP family. This allows a cross-family comparison where IPv4 and IPv6 addresses with matching leading bits are considered equal, despite being from different address spaces. This can result in incorrect classification of addresses in security controls relying on these methods. The vulnerability is addressed in version 10.7.1.

CWE-697Incorrect Comparison (opens in a new tab)
Pillar weakness
The product compares two entities in a security-relevant context, but the comparison is incorrect.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Double Encoding (opens in a new tab)
Client-side Injection-induced Buffer Overflow (opens in a new tab)
Command Delimiters (opens in a new tab)
Flash Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-843Access of Resource Using Incompatible Type (Type Confusion) (opens in a new tab)
Base weakness
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Oct 2026, 22:48 UTC

WeaknessesCWE-697, CWE-843

Technical details

References

Community reviews

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